Question

The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur. State True/False.

(a) True

(b) False

I got this question in an interview.

Question is taken from Snell Law and Critical Angle in division EM Wave Propagation of Electromagnetic Theory

Answer 1

Correct answer is (a) True

Easiest explanation: The critical angle is the minimum angle of incidence which is required for the total internal reflection to occur. This is the angle that relates the refractive index with the angle of reflection in an oblique incidence medium.